Cyro-driving and caging device

ABSTRACT

A CAGING DEVICE FOR RAPIDLY ACCELERATING A GYRO UP TO AN OPERATING SPEED OR USE, FOR EXAMPLE, IN A FLYING BODY OR A MISSILE, INCLUDES A DRIVING MECHANISM CONTAINED IN A SEPARATE HOUSING ADAPTED TO BE ATTACHED TO THE HOUSING OF THE GYRO. THE DRIVING MECHANISM INCLUDES A PISTON-NOZZLE TUBE WHICH IS SLIDABLE IN A CHAMBER FORMED AS A NOZZLE TUBE WHICH IS SLIDABLE IN A CHAMBER OF THE DRIVE HOUSING. AN ADDITIONAL CHAMBER ALONGSIDE THE PISTON CHAMBER CONTAINS A SOLID CHARGE AND AN IGNITER FUSE. THE CHANGE IS OF A SIZE TO BURN OFF AT A RATE SUFFICIENT TO PROVIDE A HIGH FLOW OF COMPRESSED GASES WHICH ARE PASSED THROUGH AN OPENING BETWEEN THE CHAMBERS INTO THE PISTON CHAMBER WHERE THE GAS INITIALLY ACTS ON THE PISTON TO DISPLACE IT SLIGHTLY IN ORDER TO RELEASE A LOCKING DETENT WHICH PREVENTS RETRACTION OF THE NOZZLE TUBE FROM THE GYRO HOUSING INTO THE NOZZLE TUBE CHAMBER. AT THE INITIAL POSITION OF THE NOZZLE TUBE PISTON, THE END THEREOF EXTENDS INTO THE GYRO CHAMBER AND THROUGH ALIGNED OPENINGS OF TWO GYRO-SUPPORT GIMBALS SO THAT THE GIMBALS ARE LOCKED AGAINST MOVEMENT DURING THE INITIAL START-UP OF THE GYRO. AFTER THE SOLID CHARGE HAS BURNED OFF, THE GAS PRESSURE REDUCES SUFFICIENTLY TO PERMIT A RETURNING SPRING TO ACT ON THE PISTON MEMBER TO PULL THE TUBE PORTION OUT OF THE GIMBALS TO PERMIT THEIR FREE PIVOTAL MOVEMENT.

March16,l971 R-KNQPP ETAL I 3,570,282

GYRO-DRIVING AND CAGING DEVICE Original Filed Nov. 3, 1967 12 24 28 L4 21 25 5O 30 2D 40 38 \s & \as 52 2s 32 2 43/ 1 2 ffil Q H12 v mvemom Rudolf Knopp Herbert Fuhr United States Patent 3,570,282 GYRO-DRIVIN G AND CAGING DEVICE Rudolf Knopp and Herbert F uhr, Munich, Germany, as-

signors to Bolkow-Gesellschaft mit beschrankter Haftung, Ottobrunn, near Munich, Germany Continuation of application Ser. No. 680,413, Nov. 3, 1967. This application Sept. 5, 1969, Ser. No. 856,904 Claims priority, applications 3(getrmany, Dec. 15, 1966,

Int. Cl. G01c 19/26 US. Cl. 745.12 2 Claims ABSTRACT OF THE DISCLOSURE A caging device for rapidly accelerating a gyro up to an operating speed or use, for example, in a flying body or a missile, includes a driving mechanism contained in a separate housing adapted to be attached to the housing of the gyro. The driving mechanism includes a piston-nozzle member having a bore therethrough and formed as a nozzle tube which is slidable in a chamber of the drive housing. An additional chamber alongside the piston chamber contains a solid charge and an igniter fuse. The charge is of a size to burn off at a rate sufficient to provide a high flow of compressed gasses which are passed through an opening between the chambers into the piston chamber where the gas initially acts on the piston to displace it slightly in order to release a locking detent which prevents retraction of the nozzle tube from the gyro housing into the nozzle tube chamber. At the initial position of the nozzle tube piston, the end thereof extends into the gyro chamber and through aligned openings of two gyro-support gimbals so that the gimbals are locked against movement during the initial start-up of the gyro. After the solid charge has burned off, the gas pressure reduces sufliciently to permit a returning spring to act on the piston member to pull the tube portion out of the gimbals to permit their free pivotal movement.

CROSS REFERENCE TO RELATED APPLICATION This application is a continuation of copending application Ser. No. 680,413, filed Nov. 3, 1967, and now abandoned.

SUMMARY OF THE INVENTION This invention relates in general to a device for driving a gyroscope and in particular to a new and useful caging device for driving a gyroscope for a short period in a device such as a missile.

In order that a gyroscope be useful for accomplishing its control function in a missile, it is necessary that the gyro be accelerated to a nominal speed in the shortest possible time before the startup of the missile so that it will be effective without being continuously driven as a reference signal transmitter during the flying time of the missile. The energy for initiating the rapid rotation of such gyros is usually taken from a compressed gas source which may be for example a powder charge such as is employed with the present invention. The size of such powder charge is determined by the acceleration energy to be expended and it is usually in the form of a cartridge with suitable protection to achieve the necessary safety for handling and storing the gyroscopes. The construction of the charge and the driving mechanism is a factor influencing the weight and space utilization inside the missile. The driving mechanism also requires that a nozzle for the passage of the compressed gases or combustion gases must be associated with the powder charge and this requires additional space. All of the driving mechanism must be designed so that it will Withstand acceleration and will function reliably even after long storage and under extreme weather conditions. The starting accelerations of such missiles runs up to 1000 times gravity and temperature diiferences of more than C. must be considered.

The known driving devices for accelerating gyros have been relatively bulky and they have been designed so that the powder charge and nozzle are arranged coaxially. Generally the powder charge is designed as a cartridge which protrudes from the housing of the driving device and closes the latter by being screwed into it. Such devices require that the gimbal frames in which the gyroscope rotor is mounted must be fixed during the driving phase in order not to change the specified reference directions at such time. The known devices for producing the gas under pressure and for delivering it through a nozzle tube to initiate rotation of the gyro and to also hold the gyro gimbals against pivotal movement have the disadvantage that they provide a great additional weight for the mechanism and do not operate efiiciently, and the arrangement of parts is such that they are not easily accessible for installation and repair.

In accordance with the present invention there is provided a caging device for driving a gyro for short periods which includes a separate housing element which may be secured in position so that it forms a wall of the gyroscope housing. The wall which is formed provides a pivot for the ball bearings of one of the gimbals of the gyro and it defines the inner end of two side-by-side chambers, one of which contains a nozzle tube piston and the other of which contains the charge for producing the pressure gases for driving the gyro rotor. The arrangement is such that the size, length and weight of the unit may be considerably reduced and the driving energy may be stored in the form of a powder charge which is easily insertable into the chamber alongside the nozzle tube chamber. A simple locking device is provided for the piston nozzle tube which locks it in a position at which the end of the nozzle tube piston engages through openings of the gimbals supporting the gyro and locks their movement.

Immediately after the formation of thrust gases by the ignition of the powder charge, the piston nozzle tube is displaced so that it frees a locking leaf spring detent from engaging behind a recess in its exterior periphery. Thereupon, the piston nozzle tube is freed and is no longer locked so that upon reduction of the pressure of the thrust gases after the powder charge has burned out, the piston nozzle tube will be displaced .in a direction away from the gyroscope housing by the force of a returning spring. The tube portion will be moved clear of the gimbals which will be permitted to pivot normally. The piston nozzle tube chamber is closed by a cover which is threaded into the open end of the driving mechanism housing. The powder charge is advantageously carried on a threaded cover member 'which also contains the igniter device for the charge. The arrangement makes it possible for the easy assembly and servicing of the driving device and of the powder charge. All components of the driving device including the powder charge can be accommodated in an acceleration-safe housing formation having no protruding parts. Half of the driving device housing may be provided for accommodating only the means for producing the gyro driving gases so that a large powder charge may be se lected.

The arrangement of the piston nozzle tube chamber and the thrust gas producing chamber alongside each other with their axes parallel prevents the combustion residues from getting into the bearings of the gyroscope rotor through the nozzle tube since the gases which are gen- 3 erated are first directed laterally from the thrust gas chamber into the piston nozzle tube chamber.

By forming a housing for the driving mechanism such that it forms a wall of the gyroscope housing, a great simplification of the assembly of the parts is achieved. In addition, the parts are accessible and visible for easy inspection.

Accordingly, it is an object of the invention to provide a device for rotating a gyro during a short period of time to bring it up to operating speed which includes a piston tube member which locks the gimbals of the gyro and which delivers gases under pressure to the gyro to effect its rotation and which is arranged in a chamber alongside a gas chamber having or generating the gyro driving gases for delivery through the nozzle tube; and wherein the piston tube is released by the build up of pressure of the gases so that it will subsequently move out of locking engagement with the gyro gimbals and after the pressure of the gases is reduced.

A further object of the invention is to provide a device for starting a gyro which includes a driving mechanism housing forming a wall of a housing for the gyro and providing a pivotal mount for one of the gimbals of the gyro and wherein a driving mechanism includes a piston tube member which is movable through an opening in the wall to block the gimbals of the gyro and with means located alongside the piston tube chamber for delivering compressed gases to the chamber for delivery through the bore thereof to rotate the gyro.

A further object of the invention is to provide a driving mechanism for a gyro which is simple in design, rugged in construction and economical to manufacture.

The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated and described a preferred embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWING The only figure of the drawing is a partial axial sectional view through a gyroscope housing and driving mechanism for the gyro constructed in accordance with the invention.

DETAILED DESCRIPTION OF THE EMBODIMENT Referring to the drawing in particular, the invention embodied therein comprises a gyroscope housing 2 having one Wall 1 which is formed by a wall of a drive housing generally designated 6. In the embodiment shown, the drive housing 6 is secured to the gyroscope housing 2 such as by suitable securing elements or bolt members 60 but of course the two housings may be formed as a single unit, if desired.

In accordance with a feature of the invention, the housing 6 is provided with a bore defining a compressed gas chamber 10 and a bore defining a piston nozzle tube chamber 12 which is substantially parallel thereto. The wall 1 is provided with an opening 7 through which a tubular end of a piston nozzle tube member generally designated 62 extends. The piston nozzle tube member 62 includes an outer cylindrical piston portion 21 which is in sealing engagement with a small diameter wall portion 24. An O-ring 29 in a groove of the piston portion 21 insures proper sealing. The bore through the piston nozzle tube member 62 includes a narrowing nozzle portion 22, a narrow central portion 23, an expanding portion 64, and a uniform diameter portion 66 which terminates at the opposite end in a discharge for directing compressed gases against blade elements 4a of a gyro 4 having rotor blades 4a shaped in the manner of a turbine, the rotor 4 being rotatable about a central axle 68.

In the embodiment illustrated, the compressed gas chamber 10 is closed at its outer end by a threaded cap 17 which forms a mounting for a support 14 which carries an annular powder charge 16. The charge 16 is designed as an annular inner and outer burner which can be ignited electrically by a fuse or igniter 18 which is mounted on the cap 17. The threaded cap 17, together with the powder charge 16 and the fuse 18 can be screwed into the chamber 10 from the open side of the housing 6 at any desired time after the assembly of the driving device and after the driving device is connected to the gyroscope. An opening 13 is defined between the walls of the chambers 10 and 12 for the flow of the compressed gas from the chamber 10 into the chamber 12.

The face of the piston nozzle tube 62 protrudes into the chamber 12 beyond a reduced dimension portion 24 in order to provide an abutting face which receives the initial pressure of the compressed gases which are di rected through the opening 13 from the chamber 10. In this position, a spring detent in the form of a leaf spring 44 engages under tension within a notch 50 and prevents a coil spring 32 arranged in an annular chamber 30 of the piston portion 21 and bearing at one end against the wall 1 from urging the piston nozzle tube member 62 toward the left, as indicated in the drawing. The piston portion 21 is dimensioned so that it is spaced from the end wall 1 when the detent 44 is locked in the recess 50. The detent 44 is held at its inner end on an extension 46 of the housing 6. An opening 25 of the housing 6 adjacent the detent is sealed by a closure member 26. Tabs 52 disposed at the location of the extension 46 hold the leaf spring in a force and form closing manner.

The gyroscope 4 is designed as a turbine rotor and it is mounted by means of inner and outer gimbal frames 38 and 40 each of which includes an opening 42 and 43, respectively, which are aligned to receive the nozzle tube 20 which extends through opening 7 of wall 1 and through the openings 42 and 43 and fixes the position of the gimbal frames so that they cannot pivot about axes 70, and 72, 72 respectively. The end wall 1 provides a mounting for ball bearings 8 to rotatably support the journal 72 for the gimbal 40.

The operation of the driving device is as follows:

The powder charge 16 is ignited at a suitable time by the igniter 18 to cause a build-up of gas pressure by combustion of the charge within the chamber 10 and the chamber 12. The initial increase in pressure in the chamber 12 causes the piston thrust tube member 62 to move to the right in a direction of the gyroscope 4 until the piston 21 strikes against the wall 1 at the inner end of the chamber 12 of the housing 6 at which time the leaf spring 44, which is under tension, will disengage from the notch 50. The release of the spring 44 unlocks the piston nozzle member 62 and permits it to be moved in a return direction toward the left under the force of the spring 32 when the pressure of the driving gases falls off after combustion is completed.

The increased gas pressure in the meantime will begin to flow through the narrow dimension portion 23 which initially acts as a choke and then flow through the constant diameter portion 66 and be discharged against the rotor 4 to cause the rotation thereof. The flow of the gas through the nozzle tube 20 causes the rotor 4 to spin at the required speed, for example 100,000 r.p.m. within the shortest possible period of time such as in about 0.3 second. The powder charge 16 is designed so that a suitable number of revolutions of the gyro 4 are obtained during the burning of this charge. When the gas pressure in the chamber 12 abates, the piston nozzle tube 62 will be moved by the pressure of the spring 32 toward the opposite end of the housing so that the gimbal frames 38 and 40 of the gyro will be released.

Chamber 12 is closed off by means of a threaded cap 34 which may be easily removed for access to the driving mechanism.

What is claimed is:

1. In a driving and caging device for accelerating a gyro of the type including a gyro housing and a turbine rotor supported by Cardan suspension gimbals in the housing, the driving and caging device being of the type including an axially displaceable tubular nozzle serving, during the temporary supply of a pressure gas thereto, to direct the gas to drive the rotor, the nozzle, before and during the pressure gas supply, being axially displaced, relative to the rotor, to a rotor driving position in which the nozzle also locks the Cardan suspension against movement and, reaxially by a spring into a retracted position in which the nozzle releases the Cardan suspension for movement, the device further including a releasable detent holding the nozzle in the driving position and releasing the nozzle at the start of the pressure gas supply: the improvement comprising a tubular piston axially displaceable in a piston bore and coaxially surrounding a substantial portion of the length of said nozzle, supporting said nozzle, and movable with said nozzle to serve as a guide for the axial movement of said nozzle; said piston having, on its outer periphery adjacent its front end facing said rotor, an abutment co-operable with said releasable detent; said piston and said nozzle conjointly defining an annular recess seating said spring; said abutment being an annular notch extending peripherally of said piston and forming a shoulder engageable with said releasable detent; said releasable detent comprising a leaf spring having a fixed end and a free end, said free end engaging said shoulder.

2. In a driving and caging device for accelerating a gyro of the type including a gyro housing and a turbine rotor supported by Cardan suspension gimbals in the housing, the driving and caging device being of the type including an axially displaceable tubular nozzle serving, during the temporary supply of a pressure gas thereto, to direct the gas to drive the rotor, the nozzle, before and during the pressure gas supply, being axially displaced, relative to the rotor, to a rotor driving position in which the nozzle also locks the Cardan suspension against movement and, responsive to diminishing of the gas pressure, being biased axially by a spring into a retracted position in which the nozzle releases the Cardan suspension for movement, the device further including a releasable detent holding the nozzle in the driving position and releasing the nozzle at the start of the pressure gas supply; the improvement comprising a tubular piston axially displaceable in a piston bore and coaxially surrounding a substantial portion of the length of said nozzle, supporting said nozzle, and movable with said nozzle to serve as a guide for the axial movement of said nozzle; said piston having, on its outer periphery adjacent its front end facing said rotor, an abutment co-operable with said releasable detent; said piston and said nozzle conjointly defining an annular recess seating said spring; said piston being formed with a outwardly facing annular groove in its external periphery; and a sealing ring seated in said groove and engaging the inner surface of said bore.

References Cited UNITED STATES PATENTS 2,415,894 2/1947 Meyer et 'al 745.12 2,960,877 11/1960 Still et al. 745.7X 3,086,400 4/1963 Barnes 745.7 3,180,223 4/1965 Rambacher et al. 745.12X 3,186,241 6/1965 Blanding et al 745.12 3,267,748 8/1966 Conklin, Ir. 745.7 3,280,643 10/1966 Frielink 745.7 3,393,569 7/1968 Lief 745.12X

FOREIGN PATENTS 796,850 6/1958 Great Britain 745.12

MANUEL A. ANTONAKAS, Primary Examiner US. Cl. X.R. 745.7 

